Air displacement devices have been developed and used to increase the supply of air and fuel to internal combustion engines to boost engine horsepower. An example of an air displacement device is the “Roots blower” shown by P. H. Roots in U.S. Pat. No. 30,157 and G. Scheerer in U.S. Pat. No. 2,201,014. Each of these devices has a belt-driven shaft that drives two close-clearance rotors. The rotating rotors during each rotation sweep out a specific volume of air to an air receiver, such as an internal combustion engine. The rotational speed of the rotors largely determines the unthrottled volume of air discharged by the device.
Internal combustion (“IC”) engine exhaust gas streams contain significant capability to perform work. The capture of this available work through the use of conventional means to benefit the IC engine in compressing its inlet air stream is often inadequate. Wave-rotor based superchargers, commonly termed Pressure Wave Supercharger (“PWS”) of current technology have not met the needs of supercharging of the internal combustion engine in a way superior to that of the conventional turbine type exhaust gas driven turbochargers, or shaft driven screw compressors or Roots blowers.
The existing PWS devices suffer from wave process designs that compromise their ability to compress aspirated air by way of efficiently exchanging work with the hot exhaust stream of the IC engine in a suitably compact unit. There exists a need to provide a supercharger design that better compress the aspirated air to a higher pressure more efficiently and to lower the final temperature in a more controllable way than conventional PWS systems.